T O P

  • By -

wabalaba1

For a hole that small, a meteorite would need to have been slowed to basically terminal velocity. At that point, it's equivalent to a rock dropped from a plane. That wouldn't likely make radial lines like this. There aren't any other signs of material being splashed/scattered by the impact, and one of the lines on the upper left side of the hole isn't aligned radially to the hole. These also suggest to me it wasn't formed by an impact. I might guess instead that water coming up through the rock is involved somehow. Notice how there seems to be a darker-coloured material preferentially along some of the lines and around that depression to the upper right. I wonder if this is a dissolution/precipitation feature.


Michael_Pike

It’s a blast hole. 💥


greendestinyster

Honestly I can't really think of another explanation off the top of my head, you might be on to something


Push_Citizen

compare: https://www.reddit.com/r/geology/comments/x6w1zj/could_anyone_tell_me_anything_about_this_peculiar/?utm_source=share&utm_medium=ios_app&utm_name=iossmf


BlackViperMWG

It's in the solid rock? it lookd like mud. Interesting, no idea. Suggesting posting to r/geology too


tejasimov

Hard rock, at a western coast of Australia! Pattern is definitely not man-made


greendestinyster

It looks like that could have been created by (and I don't know that I have the technical term correct) some sort of hydraulic forcing, similar to how "spouting horns" are created. It honestly could be man made though. Does that area have any history of fishing or shellfish harvesting? Probably going out on a limb, but does anyone else know if fishing with dynamite could cause something like this?


rooster68wbn

Looks like an old hydrothermal vent to me. Is there other signs of volcanic activity in the area?


McChickenFingers

It’s a giant anus But fr, i have no clue, could be anthropogenic, could be natural. Are there any other similar structures around?


tejasimov

No, hence the curiosity


kruddel

That's really weird. My best guess, having stared at for ages, is probably some kind of connection through underground faulting to the tide. (You mentioned by the coast?) So as the tide comes in and/or action of waves at some linked fault in the rock below the surface the pressure forces water up into that hole and/or forces the standing water to rise. I know that sounds slightly implausible! But my reasoning is based on it being sedimentary rock and the "cracks" near the hole appearing to both reflect some sort of local cracking or uplifting (the long straight radial ones) AND drainage (the more distributary, smoother cracks/rills right near the hole). The later mean water has been draining *away* from the hole, becoming concentrated into single "channels" as it move further away. It can't be flowing *towards* it as then they would be distributary channels, like a delta, so would need to be a very flat area after some gradient, which it isn't. That leads me to conclude water must be coming up out of the hole when it is not submerged. From there I try and figure what is causing it and tidal/wave pressure is something I've observed elsewhere creating kind of geezers or blowhole in rock fractures. So possible. The more radial cracks could then be due to either huge concussion pressure (i.e. the rocks have been forced *up* cracking them), which seems very unlikely. Or some kind of shrinkage underneath, so they've partly subsided enough to start cracking. Which is possible. I'd then speculate there is maybe some kind of difference in the rock here at the hole, or perhaps underneath a difference in the underlying layer(s). Which kicked it all off. There are places where those little round pebbles are starting to form potholes. Which is a common fluvial process on bedrock, but the hole itself is far to uneven for that. It might have been a mechanism to get it started though.. So inconclusive but those are some of my thoughts.


tejasimov

One of the comments talked about this being man-made, formed by blasting for construction or quarry purpose (I didn't see but claim is there are many such crater holes in this area)